Chest wall and trunk muscle activity during inspiratory loading

1992 ◽  
Vol 73 (6) ◽  
pp. 2373-2381 ◽  
Author(s):  
S. J. Cala ◽  
J. Edyvean ◽  
L. A. Engel
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Normal Subjects ◽  
Systematic Difference ◽  
Erector Spinae ◽  
Inspiratory Pressure ◽  
Emg Activity ◽  
Consistent Difference ◽  
Lung Volumes ◽  
Resistive Loading

We measured the electromyographic (EMG) activity in four chest wall and trunk (CWT) muscles, the erector spinae, latissimus dorsi, pectoralis major, and trapezius, together with the parasternal, in four normal subjects during graded inspiratory efforts against an occlusion in both upright and seated postures. We also measured CWT EMGs in six seated subjects during inspiratory resistive loading at high and low tidal volumes [1,280 +/- 80 (SE) and 920 +/- 60 ml, respectively]. With one exception, CWT EMG increased as a function of inspiratory pressure generated (Pmus) at all lung volumes in both postures, with no systematic difference in recruitment between CWT and parasternal muscles as a function of Pmus. At any given lung volume there was no consistent difference in CWT EMG at a given Pmus between the two postures (P > 0.09). However, at a given Pmus during both graded inspiratory efforts and inspiratory resistive loading, EMGs of all muscles increased with lung volume, with greater volume dependence in the upright posture (P < 0.02). The results suggest that during inspiratory efforts, CWT muscles contribute to the generation of inspiratory pressure. The CWT muscles may act as fixators opposing deflationary forces transmitted to the vertebral column by rib cage articulations, a function that may be less effective at high lung volumes if the direction of the muscular insertions is altered disadvantageously.

scholarly journals Respiratory dynamics during laughter

2001 ◽  
Vol 90 (4) ◽  
pp. 1441-1446 ◽  
Author(s):  
Mario Filippelli ◽  
Riccardo Pellegrino ◽  
Iacopo Iandelli ◽  
Gianni Misuri ◽  
Joseph R. Rodarte ◽  
...  
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Dynamic Compression ◽  
Three Dimensional ◽  
Normal Subjects ◽  
Average Frequency ◽  
Abdominal Pressure ◽  
Sudden Increase ◽  
Lung Volumes ◽  
Transdiaphragmatic Pressure

Lung and chest wall mechanics were studied during fits of laughter in 11 normal subjects. Laughing was naturally induced by showing clips of the funniest scenes from a movie by Roberto Benigni. Chest wall volume was measured by using a three-dimensional optoelectronic plethysmography and was partitioned into upper thorax, lower thorax, and abdominal compartments. Esophageal (Pes) and gastric (Pga) pressures were measured in seven subjects. All fits of laughter were characterized by a sudden occurrence of repetitive expiratory efforts at an average frequency of 4.6 ± 1.1 Hz, which led to a final drop in functional residual capacity (FRC) by 1.55 ± 0.40 liter ( P < 0.001). All compartments similarly contributed to the decrease of lung volumes. The average duration of the fits of laughter was 3.7 ± 2.2 s. Most of the events were associated with sudden increase in Pes well beyond the critical pressure necessary to generate maximum expiratory flow at a given lung volume. Pga increased more than Pes at the end of the expiratory efforts by an average of 27 ± 7 cmH2O. Transdiaphragmatic pressure (Pdi) at FRC and at 10% and 20% control forced vital capacity below FRC was significantly higher than Pdi at the same absolute lung volumes during a relaxed maneuver at rest ( P < 0.001). We conclude that fits of laughter consistently lead to sudden and substantial decrease in lung volume in all respiratory compartments and remarkable dynamic compression of the airways. Further mechanical stress would have applied to all the organs located in the thoracic cavity if the diaphragm had not actively prevented part of the increase in abdominal pressure from being transmitted to the chest wall cavity.

Breathing at low lung volumes and chest strapping: a comparison of lung mechanics

1981 ◽  
Vol 50 (3) ◽  
pp. 650-657 ◽  
Author(s):  
N. J. Douglas ◽  
G. B. Drummond ◽  
M. F. Sudlow
Keyword(s):  
Lung Volume ◽  
Maximum Flow ◽  
Normal Subjects ◽  
Lung Mechanics ◽  
Lung Volumes ◽  
Flow Rates ◽  
Recoil Pressure ◽  
Forced Expiratory Flow ◽  
Expiratory Flow ◽  
Expiratory Flow Rates

In six normal subjects forced expiratory flow rates increased progressively with increasing degrees of chest strapping. In nine normal subjects forced expiratory flow rates increased with the time spent breathing with expiratory reserve volume 0.5 liters above residual volume, the increase being significant by 30 s (P less than 0.01), and flow rates were still increasing at 2 min, the longest time the subjects could breathe at this lung volume. The increase in flow after low lung volume breathing (LLVB) was similar to that produced by strapping. The effect of LLVB was diminished by the inhalation of the atropinelike drug ipratropium. Quasistatic recoil pressures were higher following strapping and LLVB than on partial or maximal expiration, but the rise in recoil pressure was insufficient to account for all the observed increased in maximum flow. We suggest that the effects of chest strapping are due to LLVB and that both cause bronchodilatation.

Respiratory and Laryngeal Function During Whispering

1991 ◽  
Vol 34 (4) ◽  
pp. 761-767 ◽  
Author(s):  
Elaine T. Stathopoulos ◽  
Jeannette D. Hoit ◽  
Thomas J. Hixon ◽  
Peter J. Watson ◽  
Nancy Pearl Solomon
Keyword(s):  
Young Adults ◽  
Chest Wall ◽  
Voice Disorders ◽  
Normal Subjects ◽  
High Rate ◽  
Lung Volumes ◽  
Laryngeal Function ◽  
Tracheal Pressure ◽  
Lower Lung ◽  
Resistive Loads

Established procedures for making chest wall kinematic observations (Hoit & Hixon, 1987) and pressure-flow observations (Smitheran & Hixon, 1981) were used to study respiratory and laryngeal function during whispering and speaking in 10 healthy young adults. Results indicate that whispering involves generally lower lung volumes, lower tracheal pressures, higher translaryngeal flows, lower laryngeal airway resistances, and fewer syllables per breath group when compared to speaking. The use of lower lung volumes during whispering than speaking may reflect a means of achieving different tracheal pressure targets. Reductions in the number of syllables produced per breath group may be an adjustment to the high rate of air expenditure accompanying whispering compared to speaking. Performance of the normal subjects studied in this investigation does not resemble that of individuals with speech and voice disorders characterized by low resistive loads.

Gravity effects on upper airway area and lung volumes during parabolic flight

1998 ◽  
Vol 84 (5) ◽  
pp. 1639-1645 ◽  
Author(s):  
Maurice Beaumont ◽  
Redouane Fodil ◽  
Daniel Isabey ◽  
Frédéric Lofaso ◽  
Dominique Touchard ◽  
...  
Keyword(s):  
Lung Volume ◽  
Parabolic Flight ◽  
Upper Airway ◽  
Normal Subjects ◽  
Lung Volumes ◽  
Acoustic Reflection ◽  
Volume Functional ◽  
Airway Caliber ◽  
Gravity Effects ◽  
Residual Capacity

We measured upper airway caliber and lung volumes in six normal subjects in the sitting and supine positions during 20-s periods in normogravity, hypergravity [1.8 + head-to-foot acceleration (Gz)], and microgravity (∼0 Gz) induced by parabolic flights. Airway caliber and lung volumes were inferred by the acoustic reflection method and inductance plethysmography, respectively. In subjects in the sitting position, an increase in gravity from 0 to 1.8 +Gz was associated with increases in the calibers of the retrobasitongue and palatopharyngeal regions (+20 and +30%, respectively) and with a concomitant 0.5-liter increase in end-expiratory lung volume (functional residual capacity, FRC). In subjects in the supine position, no changes in the areas of these regions were observed, despite significant decreases in FRC from microgravity to normogravity (−0.6 liter) and from microgravity to hypergravity (−0.5 liter). Laryngeal narrowing also occurred in both positions (about −15%) when gravity increased from 0 to 1.8 +Gz. We concluded that variation in lung volume is insufficient to explain all upper airway caliber variation but that direct gravity effects on tissues surrounding the upper airway should be taken into account.

Psychophysics of inspiratory muscle force

1983 ◽  
Vol 54 (5) ◽  
pp. 1216-1221 ◽  
Author(s):  
D. G. Stubbing ◽  
E. H. Ramsdale ◽  
K. J. Killian ◽  
E. J. Campbell
Keyword(s):  
Lung Volume ◽  
Muscle Force ◽  
Psychophysical Function ◽  
Normal Subjects ◽  
Inspiratory Muscle ◽  
Inspiratory Pressure ◽  
Sensory Magnitude ◽  
Rib Cage ◽  
Muscle Groups ◽  
The Relationship

The perceived magnitude of static inspiratory muscle pressure was studied in normal subjects using psychophysical techniques. The sensory magnitude of a range of inspiratory pressures increased as the magnitude of the pressure increased. When the duration of the inspiratory pressure was controlled, the sensory magnitude also increased as duration increased. The relationship can be described by a single psychophysical function, psi = k x P1.234 x t0.62, where psi is perceived magnitude, P is inspiratory pressure, t is duration, and k is a constant. Use of different muscle groups and changes in lung volume altered the perceived magnitude of static inspiratory pressures. When static inspiratory pressures were generated by the abdomen-diaphragm, the perceived magnitude was significantly greater (P less than 0.01) than when they were generated by the rib cage. When lung volume was increased, the perceived magnitude of pressure was reduced. The results show that the perceived magnitude of static inspiratory pressures is affected by the pressure itself, pressure duration, the muscles used, and the lung volume at which the pressure is generated.

Factors influencing the concentration of expired nitrogen after a breath of oxygen

1965 ◽  
Vol 20 (1) ◽  
pp. 103-109 ◽  
Author(s):  
R. J. Mills ◽  
P. Harris
Keyword(s):  
Chest Wall ◽  
Lung Volume ◽  
Normal Subjects ◽  
Time Constants ◽  
Alveolar Air ◽  
Initial Volume ◽  
Single Breath ◽  
Factors Influencing ◽  
Inspired Oxygen

In normal subjects, the change in the concentration of nitrogen in expired alveolar air after a single breath of oxygen has been found to be affected by the presence of a pause at the end of inspiration, by varying rates of expiration, and by variations in the initial volume of air in the lungs. The effects of these different respiratory maneuvers are analyzed in terms of the over-all dilution of the inspired oxygen, of the unequal and asynchronous movements of the chest wall, and of the presence of a distribution of ventilatory time constants. The evidence suggests that there is a greater uniformity of ventilatory time constants at a middle lung volume than at a high or low lung volume. distribution of ventilation Submitted on January 27, 1964

Influence of passive changes of lung volume on upper airways

1990 ◽  
Vol 68 (5) ◽  
pp. 2159-2164 ◽  
Author(s):  
F. Series ◽  
Y. Cormier ◽  
M. Desmeules
Keyword(s):  
Lung Volume ◽  
Airway Resistance ◽  
Upper Airway ◽  
Normal Subjects ◽  
Base Line ◽  
Nasal Resistance ◽  
Inspiratory Flow Rate ◽  
Upper Airways ◽  
Lung Volumes ◽  
Bias Flow

The total upper airway resistances are modified during active changes in lung volume. We studied nine normal subjects to assess the influence of passive thoracopulmonary inflation and deflation on nasal and pharyngeal resistances. With the subjects lying in an iron lung, lung volumes were changed by application of an extrathoracic pressure (Pet) from 0 to 20 (+Pet) or -20 cmH2O (-Pet) in 5-cmH2O steps. Upper airway pressures were measured with two low-bias flow catheters, one at the tip of the epiglottis and the other in the posterior nasopharynx. Breath-by-breath resistance measurements were made at an inspiratory flow rate of 300 ml/s at each Pet step. Total upper airway, nasal, and pharyngeal resistances increased with +Pet [i.e., nasal resistance = 139.6 +/- 14.4% (SE) of base-line and pharyngeal resistances = 189.7 +/- 21.1% at 10 cmH2O of +Pet]. During -Pet there were no significant changes in nasal resistance, whereas pharyngeal resistance decreased significantly (pharyngeal resistance = 73.4 +/- 7.4% at -10 cmH2O). We conclude that upper airway resistance, particularly the pharyngeal resistance, is influenced by passive changes in lung volumes, especially pulmonary deflation.

Effects of thoracic volume and shape on electromechanical coupling in abdominal muscles

1984 ◽  
Vol 56 (5) ◽  
pp. 1294-1301 ◽  
Author(s):  
A. R. Hill ◽  
D. L. Kaiser ◽  
D. F. Rochester
Keyword(s):  
Lung Volume ◽  
Electromechanical Coupling ◽  
Muscle Length ◽  
Normal Subjects ◽  
Abdominal Muscle ◽  
Abdominal Muscles ◽  
Lung Volumes ◽  
Residual Capacity ◽  
Abdominal Surface ◽  
The Relationship

To assess the effects of lung volume and chest wall configuration on electromechanical coupling of the abdominal muscles, we examined the relationship between abdominal muscle pressure ( Pmus ) and electrical activity ( EMGab ) in eight normal subjects during expiratory efforts at lung volumes ranging from functional residual capacity (FRC) to FRC + 2.0 liters. At and above FRC, increases of lung volume did not significantly alter either the Pmus - EMGab relationship or abdominal surface linear dimensions, although expiratory efforts displaced the abdomen inward from its relaxed position. We attribute the constancy of delta Pmus /delta EMG above FRC to the negligible effects of increasing lung volume on abdominal configuration and muscle length. Expiratory efforts performed at lung volumes below FRC resulted in a wider range of abdominal indrawing . Under these conditions the EMGab required to augment Pmus by 30–40 cmH2O increased as the abdomen was displaced inward. This decrease of delta Pmus /delta EMGab appears to reflect muscle shortening, flattening of the abdominal wall, and possibly deformation of the rib cage.

Hypoxemia during apnea in normal subjects: mechanisms and impact of lung volume

1983 ◽  
Vol 55 (6) ◽  
pp. 1777-1783 ◽  
Author(s):  
L. J. Findley ◽  
A. L. Ries ◽  
G. M. Tisi ◽  
P. D. Wagner
Keyword(s):  
Lung Volume ◽  
Compartment Model ◽  
Normal Subjects ◽  
Breath Holding ◽  
Lung Volumes ◽  
Single Compartment ◽  
Single Compartment Model ◽  
Alveolar Hypoventilation ◽  
Arterial O2 Saturation ◽  
Voluntary Breath Holding

Seven normal awake males were studied to define the mechanisms and impact of lung volume on the hypoxemia occurring during apnea. During repeated 30-s voluntary breath holding, these subjects were studied at different lung volumes, during various respiratory maneuvers, and in the sitting and supine body positions. Analysis of expired gases and arterial O2 saturation during these repeated breath holdings yielded the following conclusions. Apnea of 30-s duration at low lung volumes is accompanied by severe arterial O2 desaturation in normal awake subjects. Initial lung volume is the most important determinant of hypoxemia during apnea. The hypoxemia of apnea at most lung volumes can be explained by simple alveolar hypoventilation in a uniform lung. The lung does not behave as a single-compartment model at lung volumes at which dependent airways are susceptible to closure.

Neuromuscular and mechanical responses to inspiratory resistive loading during sleep

1987 ◽  
Vol 63 (2) ◽  
pp. 603-608 ◽  
Author(s):  
D. W. Hudgel ◽  
M. Mulholland ◽  
C. Hendricks
Keyword(s):  
Tidal Volume ◽  
Chest Wall ◽  
Muscle Activity ◽  
Airway Resistance ◽  
Upper Airway ◽  
Inspiratory Muscle ◽  
Emg Activity ◽  
Resistive Load ◽  
Upper Airway Resistance ◽  
Resistive Loading

The purposes of this study were 1) to characterize the immediate inspiratory muscle and ventilation responses to inspiratory resistive loading during sleep in humans and 2) to determine whether upper airway caliber was compromised in the presence of a resistive load. Ventilation variables, chest wall, and upper airway inspiratory muscle electromyograms (EMG), and upper airway resistance were measured for two breaths immediately preceding and immediately following six applications of an inspiratory resistive load of 15 cmH2O.l–1 X s during wakefulness and stage 2 sleep. During wakefulness, chest wall inspiratory peak EMG activity increased 40 +/- 15% (SE), and inspiratory time increased 20 +/- 5%. Therefore, the rate of rise of chest wall EMG increased 14 +/- 10.9% (NS). Upper airway inspiratory muscle activity changed in an inconsistent fashion with application of the load. Tidal volume decreased 16 +/- 6%, and upper airway resistance increased 141 +/- 23% above pre-load levels. During sleep, there was no significant chest wall or upper airway inspiratory muscle or timing responses to loading. Tidal volume decreased 40 +/- 7% and upper airway resistance increased 188 +/- 52%, changes greater than those observed during wakefulness. We conclude that 1) the immediate inspiratory muscle and timing responses observed during inspiratory resistive loading in wakefulness were absent during sleep, 2) there was inadequate activation of upper airway inspiratory muscle activity to compensate for the increased upper airway inspiratory subatmospheric pressure present during loading, and 3) the alteration in upper airway mechanics during resistive loading was greater during sleep than wakefulness.

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